Contact Jon Soderberg-Vintage Amp Repair. Awesome pair of monos don't risk em get them fixed.
Threshold SA/1 monoblocks cap issues, perhaps?
Few weeks back I bought these monoblocks and added to my system consisting of Metrum Adagio, EAR 868L, Focal 1038BE and laptop working as a source which will be replaced with a custom made computer based transport in few weeks.
But these monoblocks seems to have few issues though the seller told me that everything was fine with these monsters.
1. There is big thump when I switch on these amps one by one and also within a second I hear a high frequency sound like "ptakk" from both sides. This sound is there while switching off the amp though less frequently and intensity IMO.
2. Initially I thought the sound is only while switching on and off but later I found that it is also there in between while the music is playing. This is more like "karr-karr" like.
3. One day I also heard it even when I switched off amp while rest of system was on. So I am thinking it might be due to leaky caps. All the caps look like in really good condition and seller told me that there is no need to chnage these as these have hardly been used. Even I use these for 20-30 min per day five times week.
4. Once I removed EAR868 from the chain and same issue was still there indicating EAR is not the criminal here. Adagi was working fine with Parasound Halo A21 which I had earlier before I added preamp and monoblocks.
I do not have much knowledge but I can learn quickly. Need the advise of experts as I really love the sound signatures of these monos.
But these monoblocks seems to have few issues though the seller told me that everything was fine with these monsters.
1. There is big thump when I switch on these amps one by one and also within a second I hear a high frequency sound like "ptakk" from both sides. This sound is there while switching off the amp though less frequently and intensity IMO.
2. Initially I thought the sound is only while switching on and off but later I found that it is also there in between while the music is playing. This is more like "karr-karr" like.
3. One day I also heard it even when I switched off amp while rest of system was on. So I am thinking it might be due to leaky caps. All the caps look like in really good condition and seller told me that there is no need to chnage these as these have hardly been used. Even I use these for 20-30 min per day five times week.
4. Once I removed EAR868 from the chain and same issue was still there indicating EAR is not the criminal here. Adagi was working fine with Parasound Halo A21 which I had earlier before I added preamp and monoblocks.
I do not have much knowledge but I can learn quickly. Need the advise of experts as I really love the sound signatures of these monos.
- ...
- 16 posts total
Threshold SA1 Mono blocks used four 29000uF/75V capacitors on each amp. You need to replace all 8 caps from both mono blocks.Diameter Is 3 Inches or 76mm. the best replacement is United Chemicon 36000uF/100V AT 95C or United Chemicon 33000uF. Cornell Dubilier is more expensive both caps are made In USA. This will solve your amp problems. |
Unfortunately I can not contact Jon as I am from India. I am not sure if he can help from that much distance. Replacing these caps is the easiest option for me as these are also available in India and price is approx. $450 for eight pieces. But I am not sure if it will solve my problem. Sometime it just might be fuse related problem. |
- 16 posts total